Harden components: add ErrorBoundary, null-safe rendering

web/client/src/App.jsx

@@ -4,6 +4,7 @@ import StorageOverview from './components/StorageOverview';
 import SmeltingPanel from './components/SmeltingPanel';
 import CraftingPanel from './components/CraftingPanel';
 import AlertsPanel from './components/AlertsPanel';
+import ErrorBoundary from './components/ErrorBoundary';
 import { useInventoryStore } from './store/inventoryStore';
 import './App.css';
 
@@ -50,7 +51,9 @@ function App() {
 
       <div className="app-content">
         <div className="sidebar">
-          <StorageOverview />
+          <ErrorBoundary>
+            <StorageOverview />
+          </ErrorBoundary>
         </div>
         <div className="main-panel">
           <div className="panel-tabs">
@@ -80,7 +83,9 @@ function App() {
             </button>
           </div>
           <div className="panel-content-wrapper">
-            {renderPanelContent()}
+            <ErrorBoundary>
+              {renderPanelContent()}
+            </ErrorBoundary>
           </div>
         </div>
       </div>